It has been attempted to recycle used absorbent articles such as disposable paper diapers. For recycling of used absorbent articles, it is common to disintegrate the used absorbent articles in water, separating them into the constituent components of the absorbent articles, which are then recovered. However, the superabsorbent polymers that are included in absorbent articles absorb moisture and increase in mass, while also gelling and losing their flow property, causing the throughput capacity of the treatment apparatus to be reduced.
In this regard, Japanese Unexamined Patent Publication No. 2010-84031 proposes a method of treating used paper diapers wherein lime, a hypochlorite and used paper diapers are loaded into a treatment tank and stirred for a prescribed period while supplying water in the minimum amount necessary for stirring in the treatment tank, the liquid in the treatment tank is discharged out of the treatment tank while dewatering, and the discharged waste water is recovered, subjected to water quality treatment and discarded.